Electrical switch



p 1947. o. H. HASSELBAUM ELECTRICAL SWITCH Filed Aug. 50, 1945 FIG. 5

BYaImL INVENTOR.

MW MJ FIG.2

Patented Sept. 9, 1947 ELECTRICAL SWITCH Oscar H. Hasselbaum,Dorchester, Mass., asslgnor to Joseph Pollak Corporation, Dorchester,Mass., a corporation of Massachusetts Application August 30, 1945,Serial No. 613,487

Claims. 1

The present invention relates to an electric switch and moreparticularly to a multiple position rotary switch in which one positionmay be a test position. The present invention may be used for combustionengines where one position of the switch is used as a test position andthe switch is held normally in that position during the test, returningto a normal position upon release.

In the present invention the rotation of the switch handle is opposed bya helical coil spring when the switch handle is turned to a selectedposition, as for instance, a test position which automatically forcesthe handle and the switch back to a normal position. The spring rests inan arcuate recess in the cover of the switch concentric with the turninghandle and has no effect on the position of the switch handle on otherpositions of operation.

The advantages and merits of the present invention will be morethoroughly understood from the description in the specification of anembodiment of the invention shown in the drawings, in which:

Figure 1 shows a sectional view looking towards the cover of the switchin a plane at right angles to axis about which the handle is turned.

Figure 2 shows an exploded view in section through the whole switchtaken on the line 2-2 of Figure 1.

Figures 3 and 4 show views of details shown in Figure 2, and

Figure 5 shows a face view of the switch viewing the dial.

In the drawings, i represents a casing or cover generally of thin metal,but other suitable materials may be used. This cover may be built upwith a cylindrical surrounding wall 2 from which tabs or fingers 3extend by means of which the back cover element 4 of insulating materialcarrying the contact studs and electrical connecting fuses which will beexplained in detail afterwards.

The base portion of the cover I is provided, concentrically positionedwith respect to its center, indentations or recesses 5, 6, I, 8 and 9,representing stop positions corresponding to positions I, 2, 3, 4 and 5respectively shown on the switch dial face it). The base also carries anarcuate formed recess ll concentrically positioned with respect to thecenter, over which a similarly arcuate formed plate l2 fastened to thebase is positioned, -forming a circularly shaped hole closed at one endii in which a helical coil spring I4 is contained. The plate i2 on theinner pcriphery is cut away from the base for a distance forming a slotIS in which a flat projecting finger i6 projecting'from the disc I! maybe moved in contact with the end of the helical coil spring The disc iiat its center is provided with an elongated slot i8 through which thecentral shaft l3 passes. The shaft is provided with a shoulder 20permitting elongated faces in the otherwise circular shafts tocorrespond to the shape of the slot i8. The disc i1 rests on theshoulder 20 of the shaft and is locked by its shape so that the discwill turn with the shaft. Just over the disc I! is the plate or latchmember 2| which is carried by the shaft i8 in the same manner as thedisc I! by means of the elongated slot 22 in the member 2i. The plate orlatch member 2i has a downwardly extending tabor finger 23 which ispositioned at such a radius from the shaft l9 so that it successivelywill engage the recesses 5, 6, I, 8 and 9, when the shaft is turned. Theplate 2i fits freely on the shaft iii in its slot 22 but is forcedagainst the base of the back by means of the spring 24 positioned aboutthe shaft extension 25. Bearing against the top of the spring as viewedin Figure 2, is the contact plate 26 which has an elongated slot 21 likethe slots in the members I? and 2i and similarly fits on the shaftextension 25. The contact plate 26 is of insulating material withconductive studs 28 and 29 connected by a conducting strip 30. The stud29 will make contact as the shaft is turned and the plate 26 rotateswith the contact 3! or the bus yoke 32 in the insulating plate 4.

The insulating plate 4is provided with a series of spaced contact studs32, 33, 34, 35, 36 and 31, with which the contact 28 will successivelyconnect as the shaft and the plate 26 is rotated as the stud 29 makescontact with the stud 3| and then the bus yoke 32.

The contact members on the plate 4 project slightly from the plate but athin disc 38 of this thickness with perforations matching the positionof the contact members and their shape fits over the plate to make asmooth continuous surface of metal and insulation so that the contacts28 and 28 will ride smoothly over all the opposing contact members.

The plate 4 has a central circular perforation into which the circularend 38 of the shaft it! rests when the plate 4 is brought into position,and the tabs 3, 3, 3, are bent over on the back of the plate 4. Thiscloses the switch casing and compresses the spring 24 so that the endaway from the plate 4 bears against the latch plate so that the pointer50 is in the position indicated by the legend test," then the arm IQ ofthe disc I! will be in the slot I5 compressing the spring Id. In thislatter position the switch is in test position but as the boss of themember 28 does not rest in one of the recesses in the cover, the

switch handle upon being released from the hand will return the switchand handle to the member 5 or normal position.

The handle 40 with the pointer 50 is held fast on the end of the shaftl9 by the set screw ii in the wall of the handle. The shaft I! on theinside of the case may have a retaining ring 52 which may snap into agroove on the shaft to keep the shaft position within the cover or theshaft may have a shoulder or some other pro- Jection to prevent it fromcoming out of the cover. The spring 24 serves therefore to press thecontacts 28 and 29 against the contact studs and bus bars and also topress the plate 2| against the cover for retaining the boss in themember 23 in the recesses 5 to 8 when they are engaged.

The shaft l9 beyond the cover works in an externally threaded bushing 53which is provided with a flange 54 against the outside of the cover.

The dial l0 sets on this flange and a nut 55 30 threads on the bushingto clamp the dial in place.

In the specification no wiring diagram has been shown for the switch maybe connected as desired so long as the connections are made for testposition and normal position on the connectors shown for whatever devicethe switch is to be adapted for.

Having now described my invention, I claim:

1. A switch of the type described comprising'a cover member having aflat base section, a sym- 0 metrically positioned shaft extending atright angles to the base section, said base section being recessed in anarcuate section concentric with the shaft, a cover positioned over saidarcuate section and a helical spring retained therein, a plate memberfixed on said shaft having an extending arm adapted to engage the end ofsaid spring. a second plate member also fixed on said shaft over saidfirst plate member, said second plate member having a dependent bossextending against said base section, said base section havingconcentrically spaced recesses in which said boss may engage, a switchcontact arm engaging said shaft and adapted to be rotated thereby, afixed switch contact plate closing the end of said cover,

and spring means surrounding said shaft positioned between the switchcontact arm and said second plate exerting spring forces in oppositedirections on said shaft.

2. In a switch of the type described having a test and normal operatingposition, a recessed cover, an operating shaft extending through saidcover having a handle with an indicating pointer on the external side ofsaid cover, a dial face positioned beneath said pointer at right anglesto 4 said shaft, a plate fixed to said shaft within said cover bearingagainst the inside of the cover and having an arm, a spring having 'oneend fixed in the cover and the other end in contact with said armwhereby when the shaft is rotated in one direction the spring iscompressed, and means in part fixed on said shaft and in part forcedagainst said cover for holding said shaft in position other than whensaid spring is compressed.

3. In a switch of the type described having a test and normal operatingposition, a recessed cover, an operating shaft adapted to be rotatedextending through said cover, a plate fixed to said shaft within saidcover bearing against the inside 5 of the cover and having an arm,spring means against which said arm bears when said shaft is rotated inone direction beyond-a given point for returning said shaft to aselected position, and means carried by said shaft and co-operating withrecesses in said recessed covers for fixing said selected position.

4. In a switch of the type described having a test and normal operatingposition, a recessed cover, an operating shaft adapted to be rotatedextending through said cover, a plate fixed to said shaft within saidcover bearing against the inside of the cover and having an arm, ahelical coil spring having an arcuate form positioned in an arcuaterecess in said cover concentric with said shaft, a cover over saidrecess having an opening along the inner edge of the recess throughwhich the arm of said plate moves to bear against the end of saidspring, and mean carried by said shaft and co-operating with recesses insaid cover for locking the shaft in its motion in selected positions.

5. In a switch of the type described having a test and normal operatingposition, a recessed cover, an operating shaft adapted to be rotatedextending through said cover, an arm carried by said shaft having aprojecting element adapted to engage corresponding recesses in the coverin the rotation of said shaft, a second arm carried by said shaft andspring means against which said second arm bears to return the same to aselected position when the shaft has been rotated in one directionbeyond a selected position, and spring means surrounding said shaft andbearing against said arms in a direction at right angles to their planeof rotation for maintaining tension of the arms against said cover.

OSCAR H. HASSEIBAUM.

REFERENCE S CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 946,045 Hubbard Jan. 11, 1910FOREIGN PATENTS Number Country Date 333,179 Great Britain Aug. 5, 1930

